关键词: 转基因水稻, 苏云金芽孢杆菌(Bt), 分子改造, 功能评价

Abstract: Cry proteins with protein engineering modification is an important method to producing new Bt protein. Cry  protein modification involves many techniques, such as domain swapping, site-directed mutagenesis, protein truncation, etc. We obtained a new Bt protein coding genes cryNAc by applying domain swapping and codon optimization against cry1Ab. Then cryNAc was transformed into Jijing88, which is Jilin provinces main rice cultivars, with Agrobacterium mediated. Molecular identification and insect resistance were evaluated against the transgenic descents. The results of molecular detection showed that cryNAc gene was successfully integrated into Jijing88 genome with stable expression. There were significant differences in CryNAc expression in roots, stems and leaves during various developmental stages, with the highest (2 959.73 ng/g) occurring during the grain filling stage in rice leaves and lowest (150.9 ng/g) in tillering stem. cryNAc transgenic rice showed significantly better resistance against Chilo suppressalis. Conclusively，our results supported that cryNAc can be used as a new cry gene for crop genetic improvement.

Key words: transgenic rice, Bacillus thuringiensis(Bt), molecular modification, function evaluation